WO2013045944A2

WO2013045944A2 - Smokeable element

Info

Publication number: WO2013045944A2
Application number: PCT/GB2012/052411
Authority: WO
Inventors: Peter Branton
Original assignee: British American Tobacco (Investments) Limited
Priority date: 2011-09-29
Filing date: 2012-09-28
Publication date: 2013-04-04
Also published as: GB201116777D0; WO2013045944A3; AR088445A1

Abstract

A smokeable element such as an element suitable for use in a smoking article is disclosed. The smokeable element comprises particles of a non-cellulosic porous carrier and a binder. The particles of non-cellulosic porous carrier are bound together by the binder to form the smokeable element.

Description

Smokeable Element

Smokeable elements are disclosed, including but not limited to smokable elements suitable for use in smoking articles.

Cellulose accounts for a large proportion of tobacco by weight, and is a precursor of many of the substances found in tobacco smoke.

Atomizing electronic cigarettes have been produced which do not contain cellulosic material, and which dispense tobacco extract for inhalation by the user. Generally these devices do not closely resemble standard smoking articles.

Summary

According to a first aspect, a smokeable element is provided. The smokeable element comprises particles of a non-cellulosic porous carrier, and a binder. The particles of the non-cellulosic porous carrier are bound together by the binder to form the smokeable element.

The element may further comprise an agent, which may comprise a tobacco extract, carried by the porous carrier. For example, the agent may be carried in the pores of the non-cellulosic porous carrier.

According to a second aspect, a method of making a smokeable element is provided. The method comprises using a binder to bind particles of a non- cellulosic porous carrier to form the element.

The method may further comprise applying an agent, which may comprise a tobacco extract, to the element such that the agent is carried by the non- cellulosic porous carrier of the element.

According to a third aspect, a smokeable element, which is obtainable by the method of the second aspect, is provided. According to a fourth aspect, a smoking article is provided comprising the smokeable element of either of the first or third aspects. Brief Description of Drawing

Reference is made to the accompanying drawing which illustrates an individual filter cigarette comprising a smokeable element according to an exemplary disclosed embodiment (not to scale). Detailed Description

The disclosed smokeable elements may be used in smoking articles in place of, or in addition to, standard smokeable material. Such elements, for example, can take the form of a cartridge in any desired shape such as a rod, or may be provided in other forms such as granular form for use in different types of smoking vessels. Indeed, if required, a smokeable element may be produced having a form and properties which enable it to be used in place of tobacco in a standard smoking article, such as a pipe, cigarette, or the like. In particular, a smoking article comprising the disclosed smokeable element may be produced which resembles a standard smoking article, but contains a reduced level of cellulosic material. Such a smoking article, in this case a filter cigarette, is shown in the accompanying Figure 1.

Figure 1 shows a smoking article 1 comprising a filter 2 and a smokeable element 3. The filter 2 is at the mouth end of the smoking article 1. The smokeable element 3 is in the form of a cylindrical rod, and the circumferential surface of the smokeable element 3 is wrapped in a paper wrapper 4, such as a cigarette paper. The wrapped smokeable element 3 thus resembles the tobacco rod of a standard cigarette. The smokeable element comprises particles of a non-cellulosic porous carrier, and a binder. The particles of the non-cellulosic porous carrier are bound together by the binder to form the smokeable element. In the embodiment shown, the filter 2 comprises a substantially cylindrical plug of filter material 5 wrapped in a plugwrap 6 around its circumferential surface. The wrapped smokeable element 3 is aligned with the filter 2, such that the end of the smokeable element rod abuts the end of the filter 2. The smokeable element rod 3 is joined to the filter 2 by tipping paper 7.

The smokeable element rod 3 of the embodiment shown in Figure 1 has a length of about 60mm. In general, smokeable element rods for use in this type of smoking article have a length similar to that of the tobacco rods generally used in cigarettes. The length may be, for example, greater than about 45mm, and generally greater than about 55mm, for instance having a length between 30mm and 100mm.

Smokeable element rods for use in smoking articles of the type shown in Figure 1 are generally of a uniform circular cross-sectional shape and size throughout their length. The rod 3 of the embodiment shown in Figure 1 has a

circumference of about 23mm. Generally, the smokeable element rod 3 may have a circumference of between about 10mm and 30mm. The rod circumference may be greater than about 12.5mm.

In the embodiment shown in Figure 1 , a single smokeable element rod 3 is used. In alternative embodiments, several smokeable elements may be used, aligned axially, and may be adjacent, or separated, for example, by sections of tobacco.

The smokeable element rod 3 of the embodiment shown in Figure 1 comprises particles of a porous carrier material, bound together by means of a binder. In this case, the binder is a combustible binder. The smokeable element rod 3 of this embodiment further comprises an agent, which is in this case is a tobacco extract. The tobacco extract is carried by the porous carrier material, and in particular, is carried predominantly within the pores of the porous carrier material. In use, ignition of some embodiments of the smokeable element rod may induce combustion of the binder, and thereby cause the release of the agent from the carrier. The agent may then be perceived by the user.

The smokeable element 3 of the smoking article 1 shown in Figure 1 combusts in a manner that resembles the smouldering of the tobacco rod of a standard cigarette. In particular, as the binder combusts, it loses its capacity to bind the particles of carrier material, and thus the carrier particles may be lost from the smokeable element, forming an 'ash', which has the appearance of tobacco ash. Furthermore, in use, since the agent comprises tobacco extract, tobacco compounds are released from the smokeable element 3 and may provide the user with a similar sensation to that provided by a standard cigarette. These properties of the smokeable element 3, in certain examples, arise as a

consequence of the method of production and the combination of materials used. Furthermore, the composition of the tobacco extract that may be used with the smokeable elements may easily be manipulated as desired to reduce or enhance the concentration of selected components.

Method of production of the smokeable element

Smokeable elements may be produced by a process involving using a binder to adhere particles of a porous carrier material into a single element. As the binder, and/or the particles, combust, the adhesion between the particles of porous carrier material may be reduced. Thus, the element may crumble, resembling the ash of a standard smoking article.

Porous particulate material

The porous carrier material generally has a large surface area, so that, if required, as much agent as possible may be carried, for instance in the pores of the carrier.

The porous carrier may be any relatively high surface area material. However, the porous carrier material does not comprise a cellulosic material, such as tobacco. Suitable porous carrier materials generally comprise micropores (<2nm pore diameter). Generally, the porous particulate material for use in the invention should have a high micropore volume. The material may also comprise mesopores (2-50nm diameter), which may assist the adsorption of larger molecules of the agent. The material may also comprise macropores (diameters greater than 50nm).

Carrier particles having a mean diameter of from about Ι ηι to about 5000μηι may be used. Generally particles having mean diameters less than about Ι ΟΟΟμπι, 500μπι, 400μπι, 300μπι, 200μπι, Ι ΟΟμπι, or 50μιτι may be preferable. Any suitable method may be used to obtain particles of the desired size. Generally the particles used may have a mean diameter of less than about Ι ΟΟμπι.

The carrier may be combustible, or the carrier may act as a combustion retardant. For example, a combustible carrier may be used with a non- combustible binder material, and in this case, the carrier may provide the element with the capacity to sustain a smoulder.

Any suitable porous carrier material may be used, including carbon (such as activated carbon, which may be derived from synthetic or natural sources), zeolite, silica gel, silica, silicates, alumino-silicates, sepiolite, clay, aluminium oxide (activated or not), carbonaceous resin or combinations thereof. Generally, the porous carrier material is a silica or activated carbon material. Suitable activated carbon materials may be derived from vegetable matter (such as coconut shells), or resins (such as phenolic resins).

The porous carrier material may be used as a single substance or a mixture, and/ or may be in admixture with other material.

Suitable materials for the production of vegetable based activated carbon include other nuts and nut shells, such as the shells of pistachio nuts and walnuts, and other fruit waste material, such as peach or apricot stones, palm kernels, or olive waste. Other organic matter, including untreated wheat straw, and wood material, is also suitable for use in producing suitable activated material. In general, any organic matter comprising a large proportion of cellulosic material will be suitable. Generally, coconut shell is used as a raw vegetable material because it can be used to produce a material having a robust structure with a very large surface area. It is also widely available and cheap, being essentially a waste product.

Phenolic resin may be obtained by condensing a nucleophilic component with an electrophilic cross-linking agent. The nucleophilic component may be, for example, a phenolic resin, such as a novolak resin, or another resin based upon copolymers of phenolic compounds, such as m-amino-phenol, diphenols such as resorcinol, hydroquinone, or amines such as aniline, melamine or urea with aldehydes such as formaldehyde, furfural or salicylaldehyde. The cross linking agent may be, for example, formaldehyde, furfural or hexamethylenetetramine. Generally, the resins used are novolak resins cross-linked with hexamethylene tetramine.

The condensation of the nucleophilic component with the electrophilic cross linking agent may be performed in the presence of a pore former. A pore former is particularly useful for incorporating larger pores into the material, such as mesopores and/or small macropores.

A solvent may also be used in the production of the resin. The pore former may act as a solvent. There are a large number of solvents that can be employed as pore formers. These solvents should have a viscosity that is not too high, and a boiling temperature that is sufficiently high to allow the polycondensation reaction to proceed at a reasonable rate without significant solvent evaporation. The novolak resin and the cross linking agent should also have a high solubility in the solvent. The pore former may be, for example, a diol, a diol-ether, a cyclic ester, a substituted cyclic or linear amide or an amino alcohol. Ethylene glycol and diethylene glycol may be used as pore formers. In general, the greater the pore former content, the wider the meso/macropores and the higher the pore volume. Thus, this mechanism therefore provides a convenient method of controlling the larger pore development in the cross- linked resin structures. Binder

A binder is used to adhere particles of a porous carrier material into a single element.

The binder may be an organic binder such as pectin, or an alginic binder.

Suitable alginic binders include soluble alginates, such as ammonium alginate, sodium alginate, potassium alginate, magnesium alginate, and propylene glycol alginate.

Other organic binders such as gums or gels may also be used. For example, suitable gums include guar gum, gum arable, gum ghatti, gum tragacanth, karaya, acacia, xanthan gum, locust bean, and their modified versions.

Suitable gels include agar, agarose, carrageenans, furoidan, and furcellaran.

Starches and curdlan may also be used as organic binders. A combination of binders may be used.

Generally the binder is an alginic binder.

These materials are desirable due to their availability and the acceptable character of smoke produced. Additionally, their binding capabilities make for good element formation and strength. The binder should generally be used in an amount sufficient but not significantly more than is required to adhere the particles together. Generally the binder is used in an amount (the total amount if more than one are employed) of between 3 and 40% by weight (based on the total element). The amount of binder that is required is dependent on the type of binder used and the properties of the porous carrier material.

The binder may be combustible, or the binder may act as a combustion retardant. For example, a combustible binder may be used with a non- combustible carrier material, and in this case, the binder may provide the element with the capacity to sustain a smoulder.

Formation of the element

Generally, the element is shaped for use in a smoking article resembling a standard cigarette. Thus the element may be in the form of a substantially cylindrical rod. However, in other embodiments, the element may have any other suitable shape.

Any suitable method may be used to form the particles of porous carrier into an element. The choice of method may depend on the shape and size of the element to be produced.

An extrusion process may be used to produce the element. An extrusion process may be suitable, for example, where the element is intended for use in a cigarette-like smoking article, in which one or more rod-shaped elements may be required.

Alternatively, elements may be produced by other methods, such as by the use of moulds or by direct shaping methods

In some cases, it may be desirable to form larger elements which may then be cut into one or more elements of the desired size and shape. In some embodiments, the smokeable elements may carry an agent.

A ent

In some embodiments, the element may comprise an agent. Since the element is composed of bound, porous carrier material, the fine structure of the element comprises numerous pores, cavities, and passageways between the particles, and the extent of these spaces is controlled by the size of the carrier particles, their porosity, and the binding conditions. The agent may be carried by the porous carrier within this complex structure. As a result of the means by which the agent is carried by the porous carrier material, when the element is smoked, the agent is released and may be perceived by the smoker. However, since it is not tobacco smoke that is being released, and is merely an agent, then the composition of substances released may be precisely controlled, and in particular, the

concentration of cellulose-derived compounds may be reduced.

An agent may be anything which may be carried by the carrier of the smokeable element.

The agent may be a substance which is capable of improving the resemblance of the smoking article to a standard smoking article. For example, the agent may provide the appearance of tobacco smoke. In addition, or alternatively, the agent may provide the taste and/ or odour of tobacco smoke.

In some embodiments, the agent may provide the smoking article comprising the smokeable element with a quality which differs from that of a standard smoking article. For example, it may provide a taste or aroma that is not usually associated with tobacco containing smoking articles.

Where local regulations permit, the agent may be, or include, a flavourant. As used herein, the term "flavour", "flavouring", and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste or aroma. Preferred flavourants include extracts (for example, tobacco, licorice, hydrangea, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb, wintergreen, cherry, berry, peach, apple, Drambuie, bourbon, scotch, whiskey, spearmint, peppermint, lavender, cardamon, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, or a mint oil from any species of the genus Mentha), flavour masking agents, bitterness receptor site blockers, receptor site enhancers, sweeteners (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other agents such as chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof.

Generally, the flavourant may be a tobacco flavour, and in particular, may be, or include, a tobacco extract. The tobacco extract may be produced by removing cellulose from tobacco material. In this way, the smoke produced by the smokeable element will contain a reduced level of cellulose-derived compounds.

A possible method of production of the tobacco extract is discussed in detail below.

Raw material

The tobacco material from which the tobacco extract is to be prepared may be strip, cut, shredded or ground tobacco, or tobacco dust. Generally, tobacco dust is used to prepare the extract since it is the least expensive.

Solvent Extraction

The tobacco material may be mixed with a solvent to form a tobacco slurry. The solvent may be added to the tobacco material in a ratio of between 10:1 and 50:1 , between 20:1 and 40: 1 or between 25:1 and 30:1 by weight. The solvent may be added to the tobacco material in a ratio of 27:1 by weight. The solvent may be an organic solution, but generally is an aqueous solution or is water. Generally, the solvent is water, but the solvent may also contain alcohols such as ethanol or methanol, or it can contain a surfactant, if required. Other solvents could be used, depending on the particular constituents to be extracted from the tobacco. Suitable solvents will be known to the skilled person.

Extraction Conditions

The extraction may be performed a temperature between about 15°C to about 85°C, and generally is performed at about 65°C. The tobacco slurry may be continually stirred during extraction, such that the tobacco remains in

suspension. The duration of the extraction is dependent on a number of factors, including the quantity of tobacco used, the extraction temperature, and the required concentration of the tobacco extract. The duration of the extraction may be from about 15 minutes to about two hours. For example, in some embodiments, extraction is performed for approximately 20 minutes.

During extraction, soluble tobacco components are dissolved in the solvent and thereby removed from the tobacco material. These components may include nicotine, sugars, soluble proteins, amino acids, pectins, polyphenols, and flavours.

Up to about 55% of the initial tobacco weight may become solubilised during the extraction process. Insoluble fibrous material, and in particular, cellulose, is not solubilised and therefore is not present in the tobacco extract. The terms

'soluble' and 'insoluble' are used to mean that the substance is capable, or incapable, of passing into solution in the particular solvent used. The tobacco extract may be separated from the insoluble residue by any suitable means. For example, the tobacco slurry may be filtered, with the tobacco extract being collected as the filtrate. Additionally, or alternatively, a centrifugation technique may be used, with the tobacco extract being collected as the

supernatant.

The extracted tobacco may be pressed following the initial separation, so as to remove any excess liquid (tobacco extract) from it. The final insoluble tobacco residue may therefore be in the form of a dewatered mat.

More than one cycle of extraction may be performed. For example, the insoluble tobacco residue may be further extracted using a solvent having the same, or different, chemical properties. In this way, as many soluble constituents as possible may be removed from the tobacco.

In addition, or alternatively, the extract may be recycled and applied to fresh tobacco or tobacco slurry. The collection and reapplication of tobacco extract to tobacco or tobacco slurry may be repeated a number of times, such as two, three, four or even five times. In this way, the final extract that is collected may be concentrated in soluble tobacco constituents.

Processing of the tobacco extract

The tobacco extract may be subsequently processed to enhance or reduce the concentration of particular constituents as required.

Constituents that it may be desirable to reduce in concentration could include, for example, proteins, polypeptides, amino acids, polyphenols, nitrates, amines, and nitrosamines. Generally, the levels of constituents such as sugar and nicotine should not be reduced in concentration, however, so that the flavour and smoking properties of the extracted tobacco are comparable to those of the original material. The tobacco extract is generally treated to remove proteins, polypeptides and/ or amino acids. Up to 60% of the proteins contained in the original tobacco material may be removed using an insoluble adsorbent such as hydroxyapatite or a Fuller's Earth mineral such as attapulgite or bentonite.

The tobacco extract may be treated with bentonite to remove polypeptides. Bentonite may be added to the extract in an amount of 2-4% of the weight of tobacco initially extracted. Alternatively, the tobacco extract may be added to a slurry of bentonite in water. The bentonite slurry may contain approximately 7 kg of bentonite in approximately 64 kg water. In any case, the bentonite concentration should generally be high enough to substantially reduce the protein content of the tobacco extract, but not so high as to additionally adsorb nicotine from it. Following bentonite treatment, the tobacco extract may be purified from the slurry by any suitable method. For example, centrifugation and/ or filtration may be used.

The tobacco extract may additionally, or alternatively, be treated to reduce the polyphenol concentration. Polyvinylpolypyrrolidone (PVPP) is an insoluble adsorbent for polyphenols, and is traditionally used in the brewing industry to remove polyphenols from beer. PVPP may be added to the tobacco extract in an amount of about 5-10% of the weight of tobacco initially extracted. This amount of PVPP is capable of removing from about 50% to about 90% of the

polyphenols present in the tobacco extract.

The optimum pH for removal of polyphenols from the tobacco extract by PVPP is believed to be about pH 3. The efficiency of adsorption by PVPP may therefore be increased by reducing the pH of the extract via the addition of a suitable acid, such as hydrochloric acid. In addition, or as an alternative to using PVPP to adsorb the polyphenols, one or more enzymes may be added to the tobacco extract to degrade the polyphenols. A suitable enzyme is laccase (urishiol oxidase). Substances other than proteins and/or polyphenols may also be removed from the tobacco extract. Alternative or additional enzymes, agents, or adsorbents may be used to remove other tobacco constituents from the tobacco extract, as required. Examples of further tobacco constituents that could be removed from the extract include nitrates, amines and nitrosamines.

If a plurality of constituents are to be removed from the tobacco extract, a number of treatments may be set up in series, each one comprising a different enzyme, agent or adsorbent, in order for a chosen complement of undesirable constituents to be removed. Alternatively, a plurality of enzymes, agents or adsorbents may be used simultaneously, so that the combination of constituents may be removed from the tobacco extract in a single treatment.

Following treatment of the tobacco extract to enhance or reduce the

concentration of particular constituents, the extract may be concentrated. The extract may be concentrated to a solids concentration of about 20% to about 50% by weight. Concentrations of up to about 10% solids are most efficiently achieved using reverse osmosis. A further concentration to approximately 40% solids may be achieved by means of a falling film evaporator. Other methods of concentration can be used and will be known to a person skilled in the art.

The tobacco extract may be applied to the smokeable element, and in this way, a smokeable product may be produced which provides the flavour and aroma associated with standard tobacco products. The resulting smokeable element may therefore have a similar physical form and appearance, taste, and smoking properties to standard smoking materials, but with a substantially reduced level of cellulose. Due to having reduced levels of cellulose, there is also a reduction in the concentration of cellulose-derived smoke components in the smoke produced when the smoking article containing the smokeable element is used. Indeed, since the composition and concentration of the tobacco extract may be adjusted as appropriate, the composition of the smoke produced when the smoking article is used may be closely controlled.

Additives may be added to the tobacco extract. The additive may, for example, be a deodoriser, a diluent, water, or, the additive may be a further flavourant.

Addition of the agent to the smokeable element

Addition of the agent to the element may be performed by any suitable method. For example, the agent may be sprayed onto the element. Alternatively, the element may be submersed in the agent.

The amount of agent that is added to the element depends upon a number of factors including the concentration of the agent, the capacity of the element to adsorb and retain the agent, and, the desired quantity of agent to be provided by the smokeable element.

After addition of the agent, the smokeable element may be dried, for example, to 'fix' the agent to the element. Any suitable method may be used, including passive and active drying processes.

Blocking the pores of a porous particulate material

The smokeable element consists of particles of a porous carrier material that are adhered together using a binder to form the element. In some embodiments, an agent is carried by the porous carrier, and in this case, during the production of the smokeable element, the particles of porous carrier material may be bound together using the binder before the agent is added. The particles may be bound before addition of the agent because it is desirable that as much agent as possible is bound to the smokeable element in a releasable manner. However, in these embodiments, since the agent is added after the particles of porous carrier material are bound together using the binder, the binder may to some extent clog the pores of the porous carrier, and thereby reduce the capacity of the carrier to carry agent. As a result, in these embodiments, it may be desirable to temporarily block the pores of the carrier material when the particles are bound together to prevent the binder from being adsorbed by the porous carrier. In some embodiments, a blocker may be used for this purpose.

The blocker should generally be capable of preventing the binder from obstructing the pores, and other agent carrying sites, of the porous carrier. The blocker should also be readily and (more or less) completely removable from the porous carrier once it has been formed into an element.

Any suitable material may be used as a blocker. Generally, the materials for use as a blocker are substances that are readily, and reversibly, adsorbed by the porous carrier material. The choice of blocker therefore depends on the type of porous carrier material used, and the pore size of the material. The blocker should generally also be substantially inert with respect to the binder.

Generally, water or an organic solvent may be used as a blocker. The blocker may be applied to the particles of porous carrier material by any appropriate method. Suitable methods of coating particulate material will be known to the skilled person.

Generally, the blocker is removed after the particulate carrier material has been formed into an element, but before addition of the agent.

Any suitable method may be used to remove the blocker from the porous carrier material of the element. The method used will largely depend on the choice of blocker used. The removal of the blocker should not disrupt the interaction between the binder and the carrier material, as this may reduce the strength and stability of the element. A vacuum may be used to remove the blocker from the carrier. Other methods may be used as an alternative, or in addition to the use of a vacuum. For example, chemical means may be used to dissolve or otherwise alter the chemical properties of the blocker. Enzymatic treatment may be used to digest the blocker. Gentle heating may be used to evaporate the blocker

If a larger element is produced for subsequent processing into one or more smaller elements, then the unblocking may be performed before or after the element is resized.

Processing of the element

If required, the smokeable element may be processed into one or more smaller elements. For example, the element may be prepared in long rods, and then cut to size for incorporation into smoking articles resembling standard cigarettes.

Resizing and/or reshaping of the element may be performed by any suitable method.

Additives

Where local regulations permit, the smokeable element may comprise an additive. The additive may be, for example, a combustion modifier, an aerosol generating means, a colourant, or any other substance capable of modifying the properties of the smokeable element.

The additive may be a solid, such as a powder, a liquid, such as a liquid deodoriser, water, etc, or a gas, such as an aromatic composition.

Generally, the additive may be present from 0-20% by weight of the smokeable element, and frequently the additive is present at about 5-10% by weight of the smokeable element. Suitable materials capable of colouring the material include cocoa, liquorice, caramel, chocolate or toffee, for example. Industry approved food colourants may also be used, such as El 50a (caramel), El 51 (brilliant black BN), El 53 vegetable carbon or El 55 (brown HT). If a food dye is used, it may be present at greater than about 0.5% by weight of the smokeable element.

Additives may be applied by any suitable method, which may involve application to the raw materials of the smokeable element prior to formation of the element, and/ or the additive may be applied to the smokeable element itself. For example, additive may be mixed with the binder, or added to the carrier separately before or after addition of the binder. When the additive is a colourant it may be dusted into the element after manufacture. In embodiments in which the smokeable element carries an agent, the additive may be mixed with the agent, and/ or may be added to the smokeable element before or after addition of the agent.

Modifying the burn properties

The disclosed smokeable element comprises particles of a non-cellulosic porous carrier that are adhered together to form the element using a binder. The element may be capable of sustaining a smoulder due to the combustion properties of the binder and/or porous carrier. Thus, as the element combusts, the cohesion between the particles of porous carrier material is lost, and the porous carrier material may fall away, resembling the ash produced by standard smoking articles.

To improve the burning properties of the smokeable element, the element may further comprise combustion modifiers. If required, burn additives, such as alkali metal salts of organic acids, sodium or potassium acetate, sodium or potassium citrate, or burn retardants, such as calcium or magnesium chloride, may be used in the smokeable element. Generally, combustion modifiers may be added to the smokeable element after the agent has been added. Any suitable method may be used to apply the combustion modifiers. The static burn rate of the smoking article may also be adjusted by altering the composition of the smokeable element. The diameter of the particles of porous carrier material used, the type of porous carrier material, and the amount and type of binder may all be adjusted to provide the desired burning properties of the smokeable element.

When the smoking article comprising the smokeable element is a cigarette, the static burn rate may alternatively or additionally be controlled by means of the use of different cigarette papers having different combustion properties. For example, the burn rate of the smoking article may be altered by adjusting the cigarette paper permeability, the burn additive type and quantity, and the filler properties and quantity.

When the smoking article comprising the smokeable element is a cigarette, the static burn rate is advantageously within the range of about 3mm/ min to about 8mm/min. For example, the static burn rate may be in the range of about 4- 7.5mm/min, or about 4-6mm/min.

Aerosol generating means

An aerosol generating means, such as an aerosol generating agent, may be included in the smokeable element to increase the quantity or improve the quality of the 'smoke'.

An aerosol generating agent may be present in the range of about 5-25%, such as about 7-18%, or about 10-15% by weight of the smokeable element. Generally, the aerosol generating agent may be present at about 11 % to about 13%, or about 12%, by weight of the smokeable element. Some or the entire aerosol generating agent may be encapsulated, such as microencapsulated, or stabilised in some other way. In this case, the amount of aerosol generating agent may be higher than the range given. Suitable aerosol generating agents include aerosol forming means selected from polyhydric alcohols, such as glycerol, propylene glycol and triethylene glycol; esters, such as triethyl citrate or triacetin, high boiling point hydrocarbons, or non-polyols, such as glycols, sorbitol or lactic acid, for example. A combination of aerosol generating agents may be used.

Generally, aerosol generating agents are added to the smokeable element after the agent has been added, or the aerosol generating agent may be mixed with the agent prior to addition of the agent. Any suitable method may be used to apply the aerosol generating agents.

Use of the Smokeable element

The element is suitable for use in a smoking article. As used herein, the term "smoking article" includes smokeable products such as cigarettes, cigars and cigarillos whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes and also heat-not-burn products (i.e. products in which flavour is generated from a smoking material by the application of heat without causing combustion of the material). Typically, smoking articles are provided with filters for removing constituents from the smoke.

Generally the smoking article is a cigarette. Cigarettes comprising the smokeable elements may resemble standard (tobacco- containing) cigarettes, wherein the smokeable element substantially or entirely replaces the tobacco of the rod of smokeable material. In some embodiments, the rod of smokeable material is made up only of the disclosed smokeable element, and no additional tobacco is present. In other embodiments, the rod may comprise a combination of smokeable element and tobacco. For example, the smokeable element may form a core, about which tobacco is arranged. Alternatively, the rod of smokeable material may comprise at one end a section of tobacco material, and at the other end, a smokeable element.

For use as a rod of smokeable material, the smokeable element may be wrapped in a paper wrapper, which may be, for example, a standard cigarette paper. The smoking article may be assembled by the user. For example, cigarette spills are available, into which the smoker may insert the smokeable element prior to use. Alternatively, the user may roll cigarette paper around the element, in a manner analogous to that used to produce cigarettes from loose tobacco.

The methods and systems of the present disclosure, as described above and shown in the drawings, provide for superior tobacco products and techniques for making the same. It will be apparent to those skilled in the art that various modifications and variations can be made to the element and method of the disclosed embodiments without departing from the spirit and scope of the disclosed embodiments. Thus, it is intended that the present disclosure include modifications and variations that are within the scope of the subject disclosure and equivalents.

Claims

1. A smokeable element, comprising particles of a non-cellulosic porous carrier, and a binder, wherein the particles of the non-cellulosic porous carrier are bound together by the binder to form the smokeable element.

2. A smokeable element according to claim 1 , wherein the element further comprises an agent, and the agent is carried by the non-cellulosic porous carrier.

3. A smokeable element according to claim 2, wherein the agent is carried in the pores of the non-cellulosic porous carrier.

4. A smokeable element according to either of claims 2 or 3, wherein the agent comprises a tobacco extract.

5. A smokeable element according to any of the preceding claims wherein the non-cellulosic porous carrier includes at least one of carbon, zeolite, silica gel, silica, silicates, alumino-silicates, sepiolite, clay, aluminium oxide,

carbonaceous resin, and combinations thereof.

6. A smokeable element according to any of the preceding claims wherein the non-cellulosic porous carrier is combustible.

7. A smokeable element according to any of the preceding claims wherein the binder is pectin, an alginic binder, a gum, or a gel.

8. A smokeable element according to any of the preceding claims wherein the binder is combustible.

9. A smokeable element according to any of the preceding claims further comprising an aerosol generating agent.

10. A method of making a smokeable element, the method comprising using a binder to bind particles of a non-cellulosic porous carrier to form the element.

11. A method according to claim 10, wherein the method further comprises applying an agent to the element such that the agent is carried by the non- cellulosic porous carrier.

12. A method according to claim 11 , wherein the method further comprises, before binding the particles of the non-cellulosic porous carrier to form the element, using a blocker to block the pores of the porous carrier and produce a blocked carrier

13. A method according to claim 12, wherein the method further comprises, before applying the agent to the element, removing a proportion of the blocker from the blocked carrier of the element.

14. A smokeable element obtainable by the method of any one of claims 10 to 13.

15. A smoking article comprising the smokeable element of any of claims 1 to 9, or 14.

16. A smoking article according to claim 15, wherein the smokeable element is wrapped in cigarette paper.

17. A smoking article according to either one of claims 15 or 16, comprising a filter at the mouth end.

18. A smoking article according to claim 17, wherein the filter comprises a plug of filter material wrapped in a plugwrap, and the filter is joined to the smokeable element by means of a tipping paper.